On page 14:I would want the oscillator to be running (Bit 7), to give good time keeping, correct? So it would be 0.I will be using alarm 1, not the square wave output, so bit 3,4,5,6 are of no importance, so they are 0.Bit 0 is set to 1 to enable alarm 1.Bit 0 = 1Bit 2 = 4_______= 5 = 0x05

I might set the alarm registers (0x87-0x8A) first, before enabling the alarm, but it looks like you have the basics sussed out. If the EOSC bit is set to 1, when Vcc power is not applied, the RTC won't keep time at all.

I might set the alarm registers (0x87-0x8A) first, before enabling the alarm, but it looks like you have the basics sussed out. If the EOSC bit is set to 1, when Vcc power is not applied, the RTC won't keep time at all.

Ok, but I'll be changing the alarm time 2x a day. Should I resend this after each time I change the alarm?

The control register should stay set, so does not to be reset every time the alarm is changed. I was thinking that there is a remote chance, not knowing the state of the alarm registers, that setting the A1IE bit could generate an unwanted alarm.

Ok, now I see why you said that. ...be sure the alarm's not set for a bad time before turning it on.Now to figure out how to set the alarm. I'll take a stab at it and then ask for help/corrections. Come back in 20 minutes!

It does, doesn't it? All those AxMy bits, spread over three or four registers. I wrote a library for the DS3232, check my approach there. It probably wouldn't be a huge job to adapt the library for the DS3234, the I2C calls (Wire library) would need to be changed to SPI. The registers are very similar if not identical.